Letterlede · Cold-email openers · Developer API

A harness for writing personalized openers to cold emails.

Stop pushing out AI slop in automated emails. Ledes are personalized copy with class. POST a prospect, and Letterlede returns the best opening line.

Five openers · Confidence-scored · One API call

letterlede / v1 / ledesenriching
enrichment · live signals
response · top ledes
96A fan of your orange brand. Remind me of YC, but in a good way.brand · website
92Congrats on the B, love how fast the robotics space is scaling.funding · 2wk
83Big congrats on 3 years at Trellis.tenure · 3yr
How it works

From unstructured fields to five openers.

Letterlede takes any prospect data and creates candidates for opening email sentences. It's that simple. Ingest via CSV or API.

01 · Ingest

Send over the prospect

Send over the prospect via CSV upload or API request (with MCP and CLI support).

CSV uploadREST APIMCP + CLI
02 · Enrich

We pull the fresh signals

Letterlede loads their website, researches their market, and finds the most natural opening lines.

FundingHiringLaunches
03 · Generate

Five openers, each scored

You get five human-sounding ledes, each tied to a different signal and ranked by evidence strength and freshness.

5 openersconfidence 0–100one per signal
One prospect · two approaches

The strict goal of Letterlede is to provide openers to emails that sound like a human wrote it. Humans can't exert infinite research effort, so Letterlede's openers teeter the line between personalized and realistic.

Generated Openers

generic

Hi Marcus, I hope this email finds you well! I came across Trellis Robotics and was truly impressed by your innovative work in the robotics space.

“hope this email finds you well”

As a leader in the fast-paced robotics industry, Trellis is exactly the kind of forward-thinking company we love to work with.

generic “industry leader” flattery

I wanted to reach out because I believe our solution could unlock tremendous value and drive real ROI for your team.

“unlock value · drive ROI”

Congrats on all the incredible growth at Trellis — you're clearly doing amazing things!

hollow, sourceless congratulations

I know you're busy, so I'll keep this short: I'd love to connect and show you what we're building.

“I know you're busy”

Letterlede Openers

human

Fan of the orange branding of Trellis. Emulates HubSpot in a good way.

brand color · skips if blue

Huge congrats on 3 years at Trellis.

tenure · fires past 1 year

Trellis is smart. I've lately been interested in the warehouse-robotics space.

market · skips the too-niche

Love the logo. Super geometric.

logo · one-word read

Brilliant company you're building. Like, really brilliant.

ambition · hard, complex builds

Letterlede keeps a (massive) library of these human formats and fires only the ones a company's signals support — so every opener stays short, specific, and true.

Ship openers that earn the reply,
not the spam folder.

One API call per prospect. Or batch upload a CSV. It's that easy.